PREX/CREX Nov 7, 2019 14:00

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Logistic information

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  1. Ongoing CREX prep activities: all
    1. SAM cans: Ciprian CREX-Install-Album
      • CG: vacuum seems to hold with the new cans.
      • DA: finished installation of SAMs. Everything was smooth.
    2. Update on S0 and S3 ?
      • ChG: S3: talked to Chuck and tested 4 new scintilators. Will figure out how to mount them at S3 with Dustin's help.
      • ChG: S0: could not test noise problem because the FastBus crate was down. Will work on it tomorrow. CC: this noise could come from the helicity signal. we can unplug it and see the effect.
    3. Update on BCM noise studies ?
      • CC: continued testing digital BCMs. We created "fake PITA signals" into but could not replicate problem. Will talk to J Musson to see if he has a different way to get this. KK: how large was the problem in PREX2? CC: we can see it's about 1/15 (from last week's slides). KK: if we cannot reproduce it we need to keep alert during the run.
      • CP: I suggest changing the way we read these out by putting both signals into both receivers so that the anti-correlated noise will cancel out.
      • CP: for PREX2 we can use a weighted average of the analogs to remove most of the noise.
  2. ARC energy measurements: Doug H
    • DH: "I do plan to continue with the ARC energy measurements and will provide a number for CREX"
  3. Shifts start Nov 25 ! Please Sign up for Shifts
  4. KP: the put in the diffuser and it needs to be removed before CREX. Don it keeping track of it.
  5. DJ: at the 8AM meeting Joe said we can get enough current out of the gun and the machine is trying to figure out how much energy they can get out of NL. One issue that was discovered was the C100s have o-rings that are being flaky recently. They are putting vacuum putty around them. KP: the question about energy has an impact on polarization. If they change it they will have to do another spin dance.
  6. KP: we need to discuss within the spokespeople group the optics that we want to run regarding the separation of the elastic and inelastic peaks.
  7. Target
    • SC: put Ca targets in tomorrow and do cooldown on Monday. I put in the haplog the survey results and we are aligned in x and y is 2mm off which we expect to recover when we pull vacuum.
    • SC: Assay for Ca48 tgt -> 90% Ca48, 9.6%Ca40,
    • SC: Meekins checked the controls and everything is ok.
    • SC: depending on the target cooldown we will have a tgt operator training sometime next week. we'll announce it over the prex list.
    • PK: I'll setup a cronjob this afternoon to look at the target vacuum EPICS variable.
  8. BM: all the CREX documents are the same as PREX2.


In F245

Cameron C, Adam Z, Weibin Z, Tao Z, Ye T, Eric K, Robert R,


Amali P, Chandan G, David A, Iris H, Juliette M, Mark D, Kent P, Victoria O, Caryn P, Silviu D, Jinlog Z, Paul K, Sanghwa P, Bob M, Juan Carlos C, Siyu J, KK, Jim N, Devi A, Don J,

Cannot make it

Ryan R, Dustin M